Hi, I recently bought a 2005 impreza 1.6l with an ihi rhb5 turbo (about 150 hp) and I noticed that the real boost starts over 3800-4000 rpm (100+ octane gasoline). The thing is that I dont want (for now...) more power I just want a little bit more torque at lower rpm (lets say 1000 rpm less). I checked over the internet and I saw 2 or 3 propable solutions. 1) wider exhaust pipe for lower back pressure in order to help turbo spool up faster 2) stiffer spring in wastegate actuator 3) remap ecu
What is the best to start with and because stock ecu isnt a good choice for remapping I would like a suggestion for an aftermarket one.
Thank you in advance.